Halogenated amide biocidal compounds and methods for treating water systems at near neutral to high ph

Abstract

Compounds and methods are provided for controlling microorganisms in water systems having a pH of 5 or greater. The compounds are of the formula I: wherein X, R and R 1 are as defined herein.

1 . A method for controlling microorganisms in a water system, the method comprising treating the water system with an effective amount of a compound of formula I: 
       
         
           
           
               
               
           
         
         wherein X is halogen; and 
         R and R 1  are, respectively, hydroxyalkyl and a cyano radical (—C≡N), or 
         R and R 1  are, respectively, hydrogen and an amido radical of the formula: 
       
       
         
           
           
               
               
           
         
       
       wherein the water system has a pH of 5 or greater. 
     
     
         2 . A method according to  claim 1  wherein X is bromo. 
     
     
         3 . A method according to  claim 1  wherein the compound of formula (I) is: 2,2-dibromo-2-cyano-N-(3-hydroxypropyl)acetamide; 2,2-dibromomalonamide; or mixtures thereof. 
     
     
         4 . A method according to  claim 1  wherein the water system has a pH of 7 or greater. 
     
     
         5 . A method according to  claim 1  wherein the water system has a pH of 8 or greater. 
     
     
         6 . A method according to  claim 1  wherein the water system is: cooling tower water, metal working fluids, oil and gas field injection or fracturing or produced water or fluids, oil and gas field water-based fluids, paper and pulp mill process water, oil and gas field operation system, oil and gas field transportation system, oil and gas field separation and storage systems, air washers, boiling water, wastewater, ballast water, filtration systems, paint, polymer emulsion, coatings, aqueous-based slurries and dispersed pigments, adhesives, inks, tape joint compounds, household and personal care, or aqueous-based fluids used in leather tanning applications. 
     
     
         7 . A method according to  claim 1  wherein the water system comprises a membrane-based filtration system comprising at least one semi-permeable membrane selected from at least one of: microfiltration, ultrafiltration, nanofiltration, reverse osmosis and ion exchange membranes; wherein the method comprises adding the compound of formula I to a feed solution followed by contacting the feed solution with the semi-permeable membrane. 
     
     
         8 . A method according to  claim 7  wherein the membrane-based filtration system comprises at least: i) one microfiltration or ultrafiltration membrane and ii) at least one nanofiltration or reverse osmosis membrane. 
     
     
         9 . A method according to  claim 7  wherein the feed solution has a pH of at least 9. 
     
     
         10 . A method according to  claim 7  wherein the feed solution has a pH of at least 11. 
     
     
         11 . A method according to  claim 1  wherein the microorganisms are bacteria. 
     
     
         12 . A method according to  claim 1  wherein the microorganism is a species of the genus  Legionella.    
     
     
         13 . A method according to  claim 1  wherein the microorganism is a species  Legionella  that has reproduced inside living amoeba. 
     
     
         14 . A compound of the formula (II): 
       
         
           
           
               
               
           
         
         wherein X is halogen and R 2  is hydroxyalkyl. 
       
     
     
         15 . A compound according to  claim 14  wherein X is bromo. 
     
     
         16 . A compound according to  claim 14  wherein R 2  is hydroxypropyl. 
     
     
         17 . A compound according to  claim 14  that is: 2,2-dibromo-2-cyano-N-(3-hydroxypropyl)acetamide.